Neuroendocrine response to an intravenous L-tryptophan challenge in women with premenstrual syndrome.

OBJECTIVE

To evaluate the neuroendocrine responses to an intravenous L-tryptophan challenge across the menstrual cycle in women with premenstrual syndrome (PMS) and controls.

DESIGN

Controlled clinical study.

SETTING

The Clinical Research Center of an academic research environment.

PATIENT(S): Women with PMS and healthy volunteers.

INTERVENTION(S): An intravenous L-tryptophan challenge was administered two times a week during 1 month to five subjects with prospectively documented PMS and five age- and body mass-matched controls.

MAIN OUTCOME MEASURE(S): Whole-blood serotonin, cortisol, and prolactin levels were assessed at the baseline and at 30, 50, 60, 70, 80, and 90 minutes after the challenge.

RESULT(S): Whole-blood serotonin response to the L-tryptophan challenge was blunted in the luteal phase of the menstrual cycle in subjects with PMS compared with controls. Cortisol levels differed between groups and cycle phases only at the baseline, with higher baseline cortisol levels during the luteal phase in women with PMS, whereas baseline and postchallenge prolactin levels did not differ between groups.

CONCLUSION(S): The present results support previously reported findings of alterations in tryptophan handling in women with PMS. The elevated baseline luteal phase cortisol concentrations in subjects with PMS warrants further investigation.